278 THE BIRD WATCHER 
has come under the ifffuence of sexual selection, it is 
the one sex only—almost always the male—that has 
been modified by its action, isacorrectone. Itseems 
to me more probable that where the sexes are alike, or 
where they differ markedly, and are both handsome, 
each of them has acquired such beauty as it possesses 
in accordance with the taste and choice of the opposite 
one. Darwin, though he did not consider this prob- 
able, yet recognised its possibility, as the following 
passage will show: “It may be suggested that in 
some cases a double process of selection has been 
carried on: that the males have selected the more 
attractive females, and the latter the more attractive 
males. This process, however, though it might lead 
to the modification of both sexes, would not make the 
one sex different from the other, unless, indeed, their 
tastes for the beautiful differed ; but this is a supposi- 
tion too improbable to be worth considering in the 
case of any animal excepting man. There are, how- 
ever, many animals in which the sexes resemble each 
other, both being furnished with the same ornaments, 
which analogy would lead us to attribute to the agency 
of sexual selection. In such cases it may be sug- 
gested with more plausibility that there has been a 
double or mutual process of sexual selection, the more 
vigorous and precocious females selecting the more 
attractive and vigorous males, the latter rejecting all 
except the more attractive females. But from what 
we know of the habits of animals this view is hardly 
probable, for the male is generally eager to pair with 
